QF  tHE 

tfVEESlT 


TIDES. 


BY 


D.    K      CHASE. 


BOSTON : 

RICHARD    L.    GAY    &    CO.,    PRINTERS,    63    MILK    STREET. 
1871. 


C$0771 


TIDES. 


NEW   THEORY. 


PEEFACE. 


As  the  common  theory  respecting  the  tides  is  not  entirely  satisfactory 
to  all  who  have  given  the  subject  consideration,  I  wish  to  present  some 
new  views,  which  I  trust  will  receive  the  attention  of  those  who  arc 
interested  in  this  subject. 

More  than  two  years  ago  I  hastily  prepared  and  published  a  few 
circulars,  explaining  briefly  my  views,  hoping  that  even  from  so  crude 
a  paper,  some  one  would  be  induced  to  adopt  the  chief  idea,  and  demon- 
strate it  in  such  manner,  as  to  make  it  clear  and  convincing.  All  I  have 
heard  from  those  circulars,  is  by  several  letters  received  from  distin- 
guished men,  most  of  whom  gave  encouraging  and  approving  replies, 
but  they  had  not  given  the  subject  sufficient  study  to  enable  them  to 
speak  with  confidence.  Since  that  time,  though  I  have  not  had  a -doubt 
as  to  the  correctness  of  the  main  principle,  I  have  changed  some  of  my 
views  relative  to  the  manner  of  producing  certain  results,  and  have  by 
further  contemplation  of  the  subject  acquired  some  additional  ideas.  I 
will  not  now  pretend  that  my  notions  are  correct  as  to  the  manner  cer 
tain  movements  and  conditions  of  the  water  are  brought  about,  but  I 
rely  upon  the  main  idea  of  lateral  movement,  and  will  again  hope  I  may 
say  enough  to  induce  competent  minds  to  examine  the  subject  thor- 
oughly. 


7115 


THEORY. 


THE  tides  are  caused  by  the  moon's  attraction,  causing  a  movement 
of  the  waters  on  that  part  of  the  surface  of  the  earth  where  they  can 
move  horizontally  towards  the  moon ;  that  is,  the  greatest  effect  is  pro- 
duced on  a  belt  of  water  surrounding  the  earth  where  a  line  from  the 
moon  meets  a  line  from  the  centre  of  the  earth  at  right  angles,  though 
the  influence  extends — its  effect  diminishing  each  way  from  this  belt — (that 
is,  nearer  to  and  further  from  the  moon,)  many  leagues,  probably  many 
degrees.  But  the  moon's  attraction  has  no  effect  upon  the  waters  on 
that  quarter  of  the  earth  nearest  the  moon,  because  the  earth's  vastly 
greater  attraction  is  there  in  opposition  to  the  moon's ;  nor  does  it  affect 
them  on  that  quarter  of  the  earth  furthest  from  the  moon,  because  the 
moon's  attraction  is  there  in  conjunction  with  the  earth.  It  is  upon  the 
sides,  or  outer  rim  of  the  earth,  as  seen  from  the  moon,  where  the  slight 
— and  in  all  other  respects,  imperceptible — attraction  has  its  effect  upon 
the  waters  and  moves  them,  because  the  earth's  attraction  there  offers 
little  or  no  resistance  to  their  movement. 

It  is  the  common  experience  of  all  that  water  is  agitated,  and  moved 
horizontally,  by  the  slightest  force.  A  pebble  dropped  into  the  centre 
of  a  pond,  will  make  a  perceptible  movement  of  the  whole  surface 
water.  Moderate  winds  roll  the  surface  water  of  the  ocean  into  waves. 
Great  rivers  flow  freely  towards  the  ocean,  where  the  descent  is  only  one 
inch  to  the  mile.  Thousands  of  tons  of  water  can  be  moved  horizon- 
tally, by  a  force  which  would  be  insufficient  to  raise  one  pound  perpen- 
dicularly. The  earth  holds  the  air  and  water  to  herself,  but  allows  them 
to  be  moved  horizontally  by  the  least  force ;  and  the  same  may  be  said 
of  solids  when  there  is  no  friction  or  other  hindrance.  For  instance, 
take  a  perfectly  round  and  polished  glass  ball,  upon  a  water  level  pol- 
ished glass  surface ;  a  very  slight  force  would  put  this  ball  in  motion — 
even  the  feeble  attraction  of  the  moon  would  start  it,  if  the  ball  was 
situated  on  that  part  of  the  earth's  surface  where  the  moon's  force 
would,  draw  at  right  angles  to  the  earth's  force,  and  probably  the  ball 
would  roll  towards  the  moon  many  degrees  (theoretically  perhaps  to  the 
very  point  nearest  the  moon^,  but  when  the  earth's  greater  attraction 
came  in  direct  opposition  to  the  moon's,  of  course  the  moon  would  cease 
to  have  effect. 

Let  us  suppose  the  whole  surface  of  the  earth  covered  with  water — 
the  earth  not  revolving  on  her  axis,  nor  the  moon  revolving  around  the 
earth;  and  suppose  the  moon's  attraction  just  now,  for  the  first  time  ap- 
plied. Where  shall  we  look  for  the  first  motion  in  the  heretofore  calm  wa- 
ters ?  Certainly  not  directly  underneath  the  moon,  nor  on  the  side  opposite, 
but  on  that  belt  of  water  surrounding  the  earth,  90  degrees  distant  from  the 


point  nearest  the  moon.  There  the  earth's  attraction  permits  it,  and  we  can 
imagine  the  water  slowly  sliding  towards  the  moon,  particle  making  way 
for  particle,  and  quantity  for  quantity,  until  a  movement  be  given  to  a 
belt  of  water  many  degrees  broad,  slightly  elevated  in  froat  and  slightly 
depressed  in  rear  of  the  movement ;  so  if  the  earth  and  moon  were  to 
retain  their  supposed  conditions,  the  water  would  in  time — perhaps  in  a 
few  months — come  to  rest  somewhat  elevated  above  its  former  level  on 
that  quarter  of  the  globe  nearest  the  moon,  and  equally  depressed  on  the 
opposite  quarter.  But  the  supposed  condition  is  not  the  real  one, — the 
earth  and  moon  do  revolve,  and  those  waters  which  are  now  in  position 
to  be  moved  by  the  moon's  attraction,  are  carried  forward  nearer  the 
moon  on  the  westerly  side  of  the  earth,  and  back  farther  from  her  on 
the  easterly  side,  the  moon's  attraction  gradually  losing  its  effect  upon 
them ;  while  at  the  same  time  other  waters  are  brought  to  the  sides  or 
circle  where  the  moon's  effect  is  greatest.  Thus  are  they  kept  in  mo- 
tion, those  in  low  latitudes  moving  easterly  on  one  side,  and  westerly  on 
the  other  side  of  the  earth,  while  those  in  high  northern  latitudes  are 
drawn  southerly  and  westerly  and  southerly  and  easterly ;  and  those  in 
high  southern  latitudes  are  drawn  northerly  and  easterly  and  northerly 
and  westerly. 

In  low  latitudes  the  waters  which  are  now  moving  eastward,  will  con- 
tinue in  that  direction  until  they  have  passed  under  the  moon,  and  on  to 
the  eastward  to  the  point  where  they  are  checked  by  the  moon's  attrac- 
tion in  the  opposite  direction.  There  they  will  come  to  a  stand,  and 
will  be  gradually  turned  into  a  westerly  current.  So  the  westerly  cur- 
rent continues  to  flow  westerly  until  it  passes  the  meridian  on  the  oppo- 
site side  from  the  moon,  when  it  is  gradually  checked  by  the  eastward 
attraction,  and  turned  into  an  easterly  movement. 

These,  I  conceive,  would  be  the  movements  of  the  waters,  which  the 
moon's  attraction  would  cause,  provided  the  earth  was  entirely  covered 
with  water,  as  I  have  thus  far  considered  it. 

But  the  continents  and  islands  cause  very  different  movements  from 
what  we  should  expect  if  there  were  no  obstructions.  Currents  are 
found  moving  in  every  direction,  with  various  degrees  of  velocity,  and 
the  rise  and  fall  of  tide  on  the  shores  of  different  continents  and  islands, 
varies  from  a  few  inches  to  fifty  or  sixty  feet. 

If  my  idea  as  to  the  eastward  and  westward  movements  be  correct, 
there  can  be  but  very  little  rise  in  the  unobstructed  ocean  waters, — pos- 
sibly not  more  than  two  inches  above  the  mean  level.  Hence  we  should 
conclude,  that  the  high  tides  we  find  on  our  coasts,  are  caused  by  the 
checking  of  these  movements,  whereby  the  waters  are  heaped  up  many 
feet  deep,  on  the  shores,  and  in  the  gulfs  and  bays.  It  must  be  evident, 
also,  that  these  heaped  waters  are  gradually  sloped  off,  so  they  extend 
only  a  comparatively  short  distance  from  the  shore. 

The  amount  of  tide  at  one  place  may  be  caused  by  the  direct  move- 
ment following  the  moon.  At  another  place  it  may  depend  upon  the 
direct  movement,  and  an  indirect  movement,  which  indirect  movement 
was  started  many  hours  before  the  direct  one ;  and  at  another  place  it 
may  depend  upon  the  same  combination,  assisted  by  a  reacting  move- 
ment. In  all  cases  the  rise  depends  much  upon  the  shape  of  the  coast 
to  which  the  movement  comes. 


The  size  of  the  tide  is  very  different  in  places  which  are  only  a  few 
miles  apart.  For  example,  the  range  in  some  places  on  the  Southern 
ceast  of  Ireland  is  only  three  feet,  while  just  across  the  Bristol  Channel 
the  range  is  very  high,  being  in  some  places  more  than  sixty  feet.  In 
this  instance  the  tide  movement  comes  probably  from  the  west  or  south' 
west — passes  parallel  with  the  south  end  of  Ireland,  and  is  crowded  di- 
rectly into  the  tunnel-shaped  Bristol  Channel,  where  it  is  heaped  up. 
This  and  many  other  examples  of  the  tide  being  very  high  in  some 
places,  while  it  is  very  little  in  other  places  not  far  off,  prove  that  the 
tide  is  caused  by  stopping  the  movement  of  the  water,  rather  than  by  a 
general  rise  of  the  ocean. 

It  will  be  seen  that,  as  the  moon  influences  a  broad  belt  of  water,  en- 
circling the  earth  and  including  the  polar  regions,  the  waters  of  high 
latitudes  are,  to  a  greater  or  less  extent,  constantly  affected  by  the 
moon's  attraction ;  while  those  near  the  equator  are  not  affected  at  all 
when  they  are  directly  under  the  moon,  or  when  they  are  on  the  oppo- 
site side  from  the  moon.  Nor,  is  the  moon's  influence  at  any  time  so 
great  upon  them  as  it  is  on  the  waters  of  higher  latitudes,  because  the 
greater  velocity  of  the  revolving  surface  at  the  equator,  gives  less  time 
for  the  moon's  attraction  to  create  a  movement  of  the  water.  So  this 
theory  leads  us  to  believe  that  we  should  have  the  highest  tides  in  high 
latitudes,  and  so  we  find  it,  in  fact. 

I  have  thus  far  spoken  of  the  moon  as  causing  the  tides.  The  sun 
exerts  an  influence  in  the  same  manner,  and  makes  his  tides ;  but  his  ef- 
fect upon  the  water  is  so  much  less  than  the  moon's,  his  tides  are  recog- 
nized only  as  increasing  or  diminishing  the  moon's  tides.  It  will  be  ap- 
parent that,  when  the  sun  and  moon  are  on  the  same  side  of  the  earth, 
each  moving  the  same  waters  in  the  same  direction,  we  should  have,  as 
we  do,  the  high  run  of  tides,  or  spring-tides.  I  think  it  will  also  be  evi- 
dent, that  when  the  sun  and  moon  are  ninety  degrees  apart,  that  is, — 
when  the  moon  is  making  her  tides  in  two  opposite  quarters  of  the 
globe,  and  the  sun  is  making  his  in  two  intermediate  quarters,  we  should 
have,  as  we  do,  the  low  -run  of  tides,  or  neap-tides.  It  is  known  that 
spring-tides  occur  again  when  the  sun  and  moon  are  on  opposite  sides  of 
the  earth.  This  may  not  seem  to  coincide  with  my  main  idea,  that  the  tides 
are  made  by  a  movement  of  the  waters  towards  the  foreign  attractions,  be- 
cause in  this  case  the  sun  and  moon  attract  in  opposite  directions.  I 
will  not  pretend  to  be  confident  as  to  the  mode  by  which  the  spring- 
tides are  formed  when  the  earth  is  between  the  sun  and  moon.  It  may 
be  owing  chiefly  to  the  near  approach  of  the  moon  to  the  earth.  But, 
supposing  the  earth  covered  with  water,  it  will  be  seen,  that  while  the 
moon  creates  a  movement  and  slight  elevation  towards  herself  of  the 
water  where  her  lines  of  attraction  are  tangent  to  the  earth's  surface, 
the  sun  will  create  a  lesser  movement  and  elevation  towards  himself 
from  the  same  waters.  These  two  elevations  will  at  one  time  be,  per- 
haps, several  degrees  apart;  but  when,  by  the  diurnal  motion  of  the 
earth,  they  are  carried  away  from  the  main  influence  of  the  attractions 
which  formed  them,  they  will  react  to  fill  up  the  depression  which  exists 
between  them.  This  reaction  and  combination  will  cause  an  elevation 
greater  than  the  moon's  power  alone  could  produce.  Though  this 
might  be  the  effect  if  the  earth  was  entirely  covered  with  water,  it  may 


be  quite  different  under  existing  circumstances.  The  intervening  land 
may  in  most  instances  prevent  the  combination  being  made  as  repre" 
sented,— especially  where  the  line  of  the  coast  is  at  right  angles  with  the 
lines  of  attraction;  but  in  those  cases,  the  sun's  attraction  may  augment 
the  alternate  or  reacting  tide.  The  idea  of  the  tides  being  made  by  a 
movement  of  water  towards  a  coast — the  water  being  heaped  by  stop- 
ping the  movement — would  perhaps  induce  the  thought  that  there  would 
be  no  tide  on  a  coast  where  the  moon  attracts  the  water  away  from  that 
coast,  instead  of  towards  it.  A  second  thought  would  lead  to  the  con- 
clusion that  the  reaction  must  be  nearly  equal  to  the  direct  flow  follow- 
ing the  moon.  Suppose  high  water  following  the  moon  to  be  ten  feet 
above  the  mean  level  of  the  ocean, — the  force  of  that  elevation  would 
cause  the  water  to  recede  and  fall,  so  that  near  the  shore,  low  water 
might  be  nine  feet  below  the  mean  level.  This  depression  would  of 
course  occasion  a  return  of  the  water,  so  as  to  make  the  second  tide 
nearly  as  high  as  the  first,  without  the  help  of  the  moon's  attraction. 
Under  these  circumstances,  the  sun  being  opposite  the  moon,  will  be  in 
conjunction  with  the  reacting  movement,  and  will  help  to  swell  the  al- 
ternate tide.  In  most  instances,  where  the  direction  of  the  attraction  is 
nearly  at  right  angles  with  the  line  of  the  coast,  the  alternate  or  react- 
ing tide  will  be  increased  by  a  tide-movement  from  the  northward  or 
from  the  southward — or  possibly  from  both. 

As  we  find  the  morning  tides  are  not  produced  in  the  same  way  the 
evening  tides  are,  we  should  not  expect  the  two  tides  to  be  of  the  same 
size;  and  so  it  is  found  in  most  places  they  are  not;  nor  is  the  interval 
from  morning  to  evening  tide  the  same  as  the  interval  from  evening  to 
morning  tide. 

On  the  western  coast  of  North  America  the  two  daily  tides  are  un- 
like, particularly  so  when  the  moon  has  large  southern  declination.  I 
quote  from  the  New  American  Cyclopedia:  "High  water  occurring 
about  twelve  hours  after  the  moon's  transit,  will  mark  five  feet  on  a  tide- 
staff."  (This,  we  will  suppose,  is  the  reaction  of  the  twelve  hours'  previ- 
ous tide.)  "Five  hours  afterwards,"  (this  will  be  when  the  moon  is 
seven  hours  to  the  eastward  of  that  place, )  "  low  water  will  mark  three 
and  one-half  feet,  six  hours  after  which  the  second  high  water  "  (which 
is  the  result  of  the  moon's  attraction  towards  that  coast,)  "  will  mark 
seven  and  one-half  feet,  and  seven  hours  later"  (which  is  when  the  moon 
is  six  hours  to  the  westward  of  that  place,)  "  the  second  low  water  will  fall 
to  zero." 

In  this  case  there  seems  to  be  an  agreement  between  the  facts  as  re- 
ported, and  the  probable  workings  of  the  principles  of  this  theory.  At 
least,  the  facts  are  not  inconsistent  with  the  theory. 

In  the  Gulf  of  Mexico  the  tides  are  similar  to  those  of  the  western 
coast  of  America,  though  much  smaller.  I  account  for  these  tides  by 
assuming  that  the  tide  movement  which  follows  the  moon  westward 
across  the  Atlantic,  continues  its  influence  through  the  Straits  of  Florida, 
and  so  on,  by  the  help  of  the  moon,  through  the  whole  Gulf,  thereby 
making  one  regular  tide  a  day.  Whereas,  the  reacting  Atlantic  tide, 
though  it  may  be  nearly  as  high  at  Cuba,  will  not  extend  far  into  the 
Gulf,  because  the  moon,  if  she  does  not  oppose,  will  not  assist  it.  The 
smaller  tides  of  the  Gulf  are  probably  caused  by  the  attraction  of  the 


waters  of  the  Gulf  alone.  Those  alternate  small  tides  on  the  western 
coast  of  Florida,  come  of  the  easterly  movement  from  the  westerly  side 
of  the  Gulf,  which  movement  is  not  felt  in  the  bend  of  the  coast,  be- 
tween the  Mississippi  River  and  Cape  St.  Blass,  where  there  is  only  one 
tide  a  day. 

In  the  Mediterranean,  there  is  a  small  tide  at  each  end  of  that  sea, 
while  there  is  no  perceptible  rise  in  the  middle.  This  may  be  accounted 
for  by  the  easterly  and  westerly  attractions  making  in  the  sea  a  slight 
movement,  which,  when  checked  by  the  land  at  the  ends,  raises  observ- 
able tides.  The  small  tide  at  the  head  of  the  Adriatic,  which  is  not 
observable  at  the  mouth  of  that  sea,  is  due  to  the  westerly  movement, 
which  starts  from  the  easterly  end  of  the  Mediterranean. 

One  writer  says :  "  The  Indian  Ocean  appears  to  have  high  water  on 
all  sides  at  once,  though  not  in  the  central  parts  at  the  same  time."  I 
will  not  be  confident  as  to  the  manner  of  producing  such  a  result ;  but  it 
will  be  perceived  that  by  this  theory,  it  may  be  by  the  westerly  move- 
ment which,  coming  from  the  Pacific,  is  checked  by  the  East  India  Is- 
lands, and  delayed  in  getting  past  them,  so  that,  by  the  time  the  rise 
takes  place  on  the  westerly  side  of  those  Islands,  the  moon  has  passed 
along  far  enough  to  produce  a  tide  on  the  easterly  shore  of  Africa,  by 
attraction  of  the  waters  of  the  Indian  Ocean.  Or,  it  may  be  the  tides 
are  made  by  direct  movement  on  one  side  of  the  ocean,  and  by  reaction 
on  the  other  side.  The  fact  stated,  at  least  supports  my  idea  that  there 
is  no  considerable  rise  of  water  over  a  great  extent  of  surface  at  the 
same  time ;  and  that,  while  it  is  high  water  near  the  shores,  it  may  be 
low  water  not  many  hundreds  of  miles  out  in  the  ocean. 

OCEAN  CURRENTS   CAUSED  BY  THE  TIDES. 

The  direct  tide  movement  I  conceive  to  be  very  unlike  the  currents  of 
the  ocean.  Currents  may  result  from  tide  movements,  but  the  tide  is  at 
first  independent  of  all  currents.  The  moon  has  the  effect  to  set  the 
whole  body  of  water  which  she  influences,  over  towards  herself;  east- 
ward or  westward,  as  the  case  may  be— not  materially  changing  the  rela- 
tive positions  or  movements  of  ocean  currents,  but  operating  alike, 
against  currents,  with  currents,  and  across  currents.  When  this  great 
tide  movement  comes  to  the  land,  and  the  water  is  heaped  up  by  the 
force  of  its  momentum,  it  may  in  due  time  recede  directly  back  the  way 
it  came, — or  it  may  be  thrown  to  the  right,  or  to  the  left,  according  to 
the  line  of  coast  to  which  it  comes.  The  water  then  assumes  the  nature 
of  a  current,  instead  of  tide  movement.  For  example,  the  eastward 
tide  movement  of  the  Pacific,  which  comes  upon  the  western  shores  of 
North  America,  is  thrown  southeasterly,  and  produces  a  current  parallel 
with  the  line  of  that  coast.  In  this  connexion  1  will  advance  the  idea 
that  the  moon,  by  her 'attraction  towards  a  coast,  will  bring  more  water 
to  the  coast,  than  she  will  by  her  reverse  attraction,  take  away  from  it. 
Her  attraction  does  not  make  any  considerable  effect  upon  the  water  at 
once,  nor  until  it  has,  little  by  little,  changed  the  position  of  the  particles 
over  a  long  distance.  Hence  the  approaching  movement,  initiated 
hours  before,  and  extending  thousands  of  miles  back  into  the  ocean,  will 
bring  near  to  the  coast,  a  much  greater  amount  of  water  than  the  re- 
verse attraction,  which  has  to  initiate  a  new  movement  at  the  coast,  will 


take  away.  Therefore,  we  may  presume  that  the  water  is  continually 
higher  near  the  continents,  on  both  sides  ol  the  Pacific,  than  it  is  in  the 
middle  of  that  ocean. 

In  support  of  these  views,  we  find  a  constant  current  southeastward 
along  the  western  coast  of  North  America,  transferring  the  heaped 
waters,  from  high  northern  latitudes,  down  within  ten  or  twenty  degrees 
of  the  equator — where  they  come  upon  the  elevated  water  which  seems 
to  be  held  in  the  bend  between  the  two  Americas — and  here  they  turn 
westward.  We  find  a  portion  of  the  waters  which  are  elevated  on  the 
western  coast  of  South  America,  flowing  constantly  eastward  past  Cape 
Horn  into  the  Atlantic ;  while  another  portion,  combining  with  the  cur- 
rent from  the  Antarctic,  flows  northward,  until  it  is  turned  by  the  bend 
in  that  coast.  It  then  flows  westward,  and  at  length  joins  the  waters 
from  the  north.  Thus  a  large  portion  of  the  water  which  is  brought  to 
the  western  shores  of  this  continent  by  the  moon's  attraction,  is  concen- 
trated near  the  equator,  and  carried  away  by  a  current.  Thus  also  is 
established  and  maintained,  the  fountain  head  of  that  great  equatorial 
current,  which  flows  westward  from  America  to  the  East  Indies. 

Now  for  the  western  side  of  the  Pacific  Ocean  I 

Here  we  find  the  tide  waters  of  the  north  are  thrown  by  the  slant  of 
the  Asiatic  shores,  southwestward  down  to  the  East  Indies,  where  they 
form  a  sort  of  barrier  against  the  approaching  equatorial  current,  and 
turn  a  portion  of  that  current  northward.  That  movement  initiates  the 
Japan  Stream,  which  flows  northeastward,  emptying  a  portion  of  its 
waters  through  Behring  Straits,  into  the  Arctic ;  the  balance  flowing 
eastward,  near  to  the  American  coast,  and  thence  southeasterly,  to- 
gether with  the  tide  waters  of  that  coast,  down  again  to  the  equator. 

At  the  East  Indies  again,  we  find  another  portion  of  the  equatorial 
current,  joined  with  the  elevated  tide  water,  flows  westward  past  the  Is- 
lands into  the  Indian  Ocean ;  while  the  southern  portion  of  the  great 
current  goes  southward  past  the  east  side  of  Australia,  and  there  joining 
the  northeasterly  movement  from  the  Antarctic,  flows  back  to  the 
western  shores  of  South  America,  and  thence  northward  to  the  equator 
again. 

It  will  be  seen  that  the  shores  washed  by  the  North  Pacific  seem  to  be 
particularly  adapted  to  turning  the  tide  movement  which  comes  to  those 
shores,  down  towards  the  equator,  while  the  shores  of  the  South  Pacific 
are  not  so  favorable  for  turning  the  water  northward.  Hence  more  water 
is  conveyed  from  the  north  down  to  the  equator  by  the  tide  movement, 
than  is  conveyed  northward  to  the  equator  from  the  south.  Therefore 
more  must  be  returned  from  the  equator  to  the  north.  The  great  Japan 
Stream  performs  that  service  of  returning  the  overdrawn  balance  to 
the  north,  and  we  find  no  great  current  southward. 

In  the  Indian  Ocean,  the  influx  of  the  raised  waters  of  the  west  Pa- 
cific, is  felt  by  the  current  westward  across  the  ocean  ten  to  fifteen  de- 
grees south  of  the  equator,  or  on  the  parallels  of  the  main  influx.  On 
the  western  side  of  the  ocean,  this  current,  with  the  tide  movement, 
makes  a  continual  rise  above  the  mean  level  on  the  east  coast  of  Africa. 
This  rise  causes  a  constant  current  southwestward  along  that  coast,  and 
thence  westward  around  the  south  end  of  Africa,  into  the  Sonth  At- 
lantic. 


8 

In  the  South  Atlantic,  the  influx  from  the  Indian  Ocean  is  joined  by 
the  easterly  influx  around  Cape  Horn,  and  thus  is  created  the  reservoir 
of  that  great  movement  which  goes  through  the  Atlantic, — at  first  north- 
Ward,  nearly  parallel  with  the  southwest  coast  of  Africa  to  the  bend  in 
that  coast.  Then  westward,  one  portion  going  through  the  Caribbean 
Sea,  and  out  between  Cuba  and  Florida,  while  the  other  portion  goes 
north  of  the  Islands.  The  whole  then  moves  northeastward — a  large 
portion  to  the  Arctic,  supplying  that  ocean  with  an  immense  amount  of 
warm  water,  in  exchange  for  cold  water  and  icebergs. 

The  exchange  between  the  Atlantic  and  Arctic  is  apparent.  But  it 
seems  doubtful  how  the  Pacific  and  Indian  Oceans  get  compensation 
from  the  Atlantic  and  Arctic.  It  is  partly,  no  doubt,  by  an  under- 
current southward  through  Behring  Strait — and  it  may  be  partly  by  the 
difference  in  evaporation  and  rain-fall,  or  it  may  be  by  undercurrents  in 
the  South  Atlantic. 

I  have  thus  mentioned  the  main  currents  of  the  oceans,  with  the  idea 
that  the  reader  will  see  the  connexion  they  have  with  the  primary  move- 
ments which  the  moon's  attraction  causes ;  and  that  these  currents,  be- 
ing due  directly  or  indirectly  to  the  tide  movements,  tend  to  substantiate 
my  theory. 

I  would  not  deny  that  the  trade  winds  have  a  tendency  to  guide  the 
equatorial  current — perhaps  they  accelerate  its  movements  and  augment 
its  volume;  but  I  believe  it  will,  in  time,  be  found  that  the  concentration 
of  the  tide  waters,  near  the  west  coast  of  Central  America — as  before 
represented — is  the  first  cause,  and  chief  support  of  that  great  current. 

There  is  a  current  along  the  eastern  shores  of  Asia,  which  runs  south- 
westerly inshore  of  the  Japan  Stream.  There  is  a  current  on  the 
southwest  coast  of  Africa,  which  runs  southeasterly  inshore  of  the 
great  northward  movement.  There  is  also  a  current  which  runs  south- 
westerly along  the  easterly  coast  of  North  America,  inshore  of  the  Gulf 
Stream.  None  of  these  inshore  currents  are  supposed  to  be  eddy  cur- 
rents. Now,  I  suggest  that  these  facts  support  the  ideal  have  advanced, 
that  the  water  near  the  shores  is  kept  above  the  mean  level  by  the  influ- 
ence of 'the  moon.  I  suggest,  also,  that  these  above-named  inshore 
currents,  as  well  as  the  currents  on  the  cocst  of  California,  on  the  coast 
of  Brazil,  and  on  the  eastern  coast  of  Africa,  confirm  the  statement 
that  water  moving  against  a  shore  which  lies  diagonal  to  the  course  of  the 
movement,  is  thrown  obliquely  parallel  with  the  line  of  the  coast.  These 
currents  prove  also,  that  the  tide  movement  conies  from  the  westward 
as  well  as  from  the  eastward. 

FOUNDATIONS   OF  THE   TWO  THEORIES. 

The  common  theory  teaches  that  the  waters  nearest  the  moon,  being 
attracted  with  more  force  than  the  centre  of  the  earth,  are  drawn  away 
from  the  earth,  while  the  centre  of  the  earth,  being  attracted  with  more 
force  than  the  waters  furthest  from  the  moon,  is  drawn  away  from  those 
waters.  That  theory  also  gives  as  a  reason  why  the  moon  has  greater 
influence  in  producing  tides  than  the  sun  has ;  that  the  relative  differ- 
ence in  the  distances  between  the  moon  and  the  different  portions  of  the 
earth,  is  greater  than  the  relative  difference  between  the  sun  and  the 
different  portions  of  the  earth. 


9 

As  my  theory  teaches  that  the  foreign  attractions  cause  the  tides  by 
lateral  movement,  and  therefore  the  difference  in  the  distances  has  no 
part  in  the  matter,  I  shall  be  expected  to  state  what  I  have  for  a  foun- 
dation to  my  theory, — why  the  water  is  moved  more  than  the  earth, 
which  is  equally  distant  from  the  moon,  and  why  the  moon  has  more  in- 
fluence on  the  water  than  the  sun  has. 

The  law  discovered  by  Newton,  is  as  follows:  "Every  particle  of 
matter  in  the  universe,  attracts  every  other  particle  of  matter  with  a 
force  or  power  directly  proportioned  to  the  quantity  of  matter  in  each, 
and  decreasing  as  the  squares  of  the  distances  which  separate  the  par- 
ticles increase." 

I  am  not  competent  to  make  the  mathematical  calculation  which  will 
determine  whether  or  not  my  theory  will  stand  the  test  of  this  law,  but 
when  a  trial  shall  be  made,  taking  a  portion  of  the  ocean  water  instead 
of  the  whole  earth,  as  one  of  the  quantities  in  the  calculation,  I  have  no 
doubt  the  result  will  be  favorable,  and  that  a  solid  basis  will  be  acknowl- 
edged for  a  theory  which  appears  plausible. 

I  cannot  now  do  more  than  to  give  my  own  views  in  my  own  way. 

Suppose  the  earth  annihilated,  leaving  a  cannon-ball  in  its  place,  would 
not  that  cannon-ball  tend  to  go  to  the  moon  ? 

Now,  suppose  the  solid  portion  of  the  earth  taken  away,  leaving  the 
water  in  its  stead,  would  not  that  water  fall  to  the  moon,  or,  possible, 
revolve  around  her  the  same  as  the  moon  now  revolves  around  the 
earth  ? 

If  these  questions  admit  of  affirmative  answers,  then  it  follows  that 
the  moon  will  attract  the  waters  on  the  face  of  the  earth  more  than  she 
will  the  solid  earth,  wherever  the  waters  can  be  moved  as  an  indepen- 
dent quantity,  or  without  hindrance  by  the  earth's  attraction;  and  I 
contend  that  they  can  be  moved  on  the  ninety  degree  circle  much  the 
same  as  if  they  were  floating  in  space  uninfluenced  by  the  earth.  Let 
us  take  the  sun's  influence  on  the  moon  revolving  around  the  earth,  as 
analogous  to  the  sun  and  moon's  attraction  of  the  waters. 

When  the  moon  is  receding  from  the  sun  on  one  side  of  the  earth,  her 
progress  is  retarded  by  the  sun's  attraction ; — when  she  is  approaching 
the  sun  on  the  other  side  of  the  earth,  her  progress  is  accelerated  by  his 
attraction.  Now  we  will  consider  the  water  as  revolving  around  the 
centre  of  the  earth,  4,000  miles  distant  therefrom,  the  same  as  the  moon 
revolves  240,000  miles  distant.  When  the  water  is  receding  from  the 
moon  or  sun  on  one  side  of  the  earth,  its  diurnal  progress  is  retarded, 
and  when  it  is  approaching  on  the  other  side,  its  diurnal  progress  is  ac- 
celerated. In  either  case  the  water  is  made  to  move  over  the  face  of  the 
solid  earth,  and  this  is  the  movement  which  makes  the  tides. 

If  it  be  conceded  that  in  case  the  solid  portion  of  the  earth  was  taken 
away,  leaving  the  waters  alone,  they  would  first  go  to  the  moon,  then, 
of  course,  the  moon  must  have  the  greater  influence  in  producing  tides. 
The  moon's  nearness,  as  compared  with  the  sun's,  and  her  great  mass  as 
compared  with  the  particles  of  water,  makes  her  effect  on  those  particles 
the  greatest,  notwithstanding  the  sun's  attraction  on  the  whole  earth  is 
far  greater  than  the  moon's. 

In  a  system  of  revolving  bodies,  distance,  weight  and  velocity  are  to 
be  considered.  At  a  given  distance  from  the  great  centre,  if  a  reyolv- 


10 

ing  body  be  reduced  in  weight,  velocity  must  be  added,  or  the  reduced 
body  will  tend  to  the  centre,  and  go  to  it,  or  move  in  a  new  orbit. 
Leave  the  weight  unchanged — and  reduce  the  velocity — the  result  would 
be  similar.  Leave  the  weight  and  velocity  unchanged,  and  reduce  the 
distance,  the  result  would  be  similar.  On  the  contrary,  if.  at  a  given 
distance,  the  weight  be  increased,  velocity  must  be  reduced,  &c. 

Now,  it  is  evident,  that  if  the  solid  earth  were  stricken  out,  leaving 
the  water,  or  a  small  part  of  the  water,  moving  at  the  same  rate  the 
moon  now  moves  around  the  earth,  the  water  having  so  little  weight 
would  need  greater  velocity,  or  it  would  not  keep  its  present  distance 
from  the  moon,  but  would  tend  to  go  to  it;  hence  the  tendency  in  that 
direction  where  it  can  move  without  the  earth's  hindrance. 

BESPECTING  THE  COMMON  THEORY. 

As  my  theory  must  be  false  if  the  old  be  true,  I  must  attempt  to  show 
that  the  old  theory  is  false. 

If  I  may  be  considered  presumptuous  in  attempting  to  refute  opinions 
of  the  most  celebrated  scientific  men,  I  shall  at  least  be  countenanced 
by  many,  in  saying  that  the  common  theory  of  the  tides  impresses  the 
common  mind  unfavorably ;  and  as  I  am  one  the  unbelievers  in  that 
theory.  I  should  be  permitted  to  give  some  of  the  reasons  why  I  am  so. 

That  theory  represents  that  there  exists  continually,  two  "  immensely 
broad  and  flat "  protuberances  of  water  on  two  opposite  sides  of  the 
globe ;  one  protuberance  being  raised  by  the  amount  of  attraction  which 
the  moon  has  on  the  near  waters  more  than  she  has  on  the  centre  of  the 
earth,  while  the  other  is  raised  by  the  amount  of  attraction  which  the 
moon  has  on  the  centre  of  the  earth,  more  than  she  has  on  the  remote 
waters.  In  short,  the  water  is  drawn  away  from  the  earth  on  one  side, 
and  the  earth  is  drawn  away  from  the  water  on  the  other  side. 

It  certainly  appears  as  though  the  remote  tide  could  not  be  made  as 
represented,  for,  in  fact,  the  earth  is  not  moved  by  the  moon  in  the 
least  degree,  excepting  as  she  is  swayed  a  little  by  the  moon's  revolution 
around  her.  And  as  this  revolution  is  made  only  once  in  twenty-nine 
days,  it  would  seem  that  the  only  chance  for  the  moon  to  make  a  tide 
by  drawing  the  earth  away  from  the  remote  waters,  would  be,  to  stop 
the  earth's  motion  on  her  axis,  and  have  only  the  two  tides  in  twenty- 
nine  days ;  or,  if  we  would  have  two  tides  in  a  lunar  day,  the  moon 
should  make  twenty-nine  revolutions  while  she  now  makes  but  one. 

I  cannot  conceive  how  these  immensely  broad  elevations,  which  are 
said  to  exist  at  all  times,  can  follow  the  moon  from  east  to  west;  nor  can 
I  conceive  how  they  can  be  made  to  appear  on  the  easterlv  sides  of  the 
oceans,  and  disappear  on  the  westerly  sides.  Let  us  suppose  the  vertex 
of  one  elevation  is  now  in  the  middle  of  the  Pacific,  moving  westward 
at  the  rate  of  1,000  miles  per  hour.  It  must  at  the  same  time  be  about 
low  water  at  the  Isthmus  of  Panama,  and  also  at  the  East  Indies.  In 
six  hours  the  top  of  this  immense  wave  will  be  at  the  East  Indies,  and 
make  high  water  there.  In  six  hours  more,  the  wave  will  have  disap- 
peared, and  again  it  is  low  water.  Now,  I  ask,  where  has  this  great 
wave  gone  to,  in  the  short  space  of  six  hours  ?  Certainly  not  back  east- 
ward, for  the  opposite  wave  has  meantime  appeared  on  the  eastern  side 


11 

of  the  ocean,  and  has  followed  right  on,  so  it  is  now  in  the  middle  of  the 
ocean.  In  fact,  that  theory  does  not  indicate  that  the  tide  wave  ever 
goes  eastward.  It  cannot  be  said  that  it  passed  through  the  straits  of 
the  East  Indies,  because  an  amount  of  water  equal  to  a  rise  of  six  inches 
over  so  great  an  area,  could  not  pass  through  those  straits  in  many 
months.  But  the  disappearance  of  the  wave  on  the  western  side,  is  not 
more  strange  than  the  formation  of  another  on  the  eastern  side  of  the 
ocean.  Where  has  the  vast  amount  of  water  which  has  raised  the  east- 
ern Pacific  from  low  water  to  high  water  come  from  ?  As  soon  as  one 
wave  passes  westward  out  of  the  way,  another  springs  up  and  follows, 
and  so  they  go  forever ;  still,  there  is  no  less  water  on  the  American 
side,  and  no  more  on  the  Asiatic  side.  Let  us  see  how  it  is  in  the  At- 
lantic Ocean.  As  there  is  but  little  breadth  here  for  the  slope  of  the 
tide  wave  east  and  west,  we  should  be  led  by  that  theory  to  infer,  that  at 
high  tide  the  whole  ocean  would  be  raised  as  much  as  the  average  depth 
of  the  tide  on  the  shores.  This  would  be  at  least  two  feet.  To  say 
nothing  as  to  where  this  vast  increase  of  water  comes  from,  is  it  possi- 
ble to  tell  how  it  can  escape,  so  as  to  make  low  water,  in  six  hours' 
time  ?  It  cannot  go  eastward, — it  cannot  go  westward,  unless  it  goes 
under  the  American  Continent ;  for  the  current  is  always  eastward  off 
Cape  Horn,  and  much  of  the  time  southward  in  Baffin's  Bay. 

I  know  the  supporters  of  that  theory  instruct  us  that  the  tide  protu- 
berances are  raised, — not  by  a  transfer  of  the  same  particles  or  quanti- 
ties of  water, — but  by  an  undulating  motion — a  sort  of  rising  and  sink- 
ing of  the  particles.  One  writer  says :  "  The  tidal  wave  is  entirely 
different  from  a  current ;  the  particles  of  water  merely  rise  and  fall." 
The  action  may  be  different  from  a  current,  but  if  there  be  a  rise  of  one 
foot  or  one  inch  of  water  on  a  certain  area,  the  amount  of  that  one  inch 
or  one  foot  rise,  must  be  added  in  some  way,  and  must  come  from  some 
other  locality.  We  may  conceive  how  the  common  small  waves  of  the 
sea  may  be  kept  in  existence  and  in  motion,  by  the  sinking  of  a  quantity 
of  water,  which  may  at  one  instant  constitute  a  wave,  and  the  consequent 
forcing  or  wedging  up  of  another  quantity  just  in  front,  and  this  last 
quantity  again  sinking,  and  another  rising,  and  so  on ;  thus  advancing 
the  whole  surface  water  a  little,  without  much  changing  the  location  of 
any  particular  quantity  of  water.  But  it  appears  impossible  to  under- 
stand how  a  quantity  of  water  which  raises  an  "  immensely  broad  and 
flat  wave,"  covering  one-quarter  of  the  globe,  can,  by  this  rising  and 
sinking  process,  be  moved  over  the  face  of  the  earth  at  the  rate  of  nearly 
one  thousand  miles  per  hour,  even  if  there  was  no  land  to  obstruct  its 
progress.  Admitting,  however,  that  this  undulating  motion  can  in  a 
few  hours  sink  the  surface  of  the  whole  eastern  Pacific  from  high  to  low 
water,  and  raise  the  surface  of  the  whole  western  portion  of  that  ocean 
from  low  to  high  water,  is  it  possible  for  that  sinking  and  rising  process 
to  continue  its  influence  through  the  straits  at  the  East  Indies,  so  as  to 
sink  the  western  Pacific  and  raise  the  Indian  Ocean  in  a  few  hours  more  ? 
If  there  are  reasonable  explanations  to  these  apparent  mysteries,  I 
have  not  been  able  to  see  them. 

If  the  protuberances  exist,  as  represented  by  that  theory,  the  tides 
should  be  highest  in  low  latitudes,  for  the  elevations  must  slope  from  the 
vertices  each  way,  north  and  south,  as  well  as  east  and  west.  On  the 


12 

contrary,  we  have  the  published  statements  to  show  that  the  average 
rise  and  fall  is  more  in  high  latitudes  than  it  is  in  low. 

The  fact  that  we  have  spring  tides  when  the  sun  and  moon  are  on  op- 
posite sides  of  the  earth,  appears  to  be  inconsistent  with  that  theory. 
For,  though  the  moon,  by  her  near  approach,  may  raise  more  tide  on  the 
mear  side,  how  can  she  influence  the  earth,  so  as  to  make  more  tide  on 
the  remote  side,  while  the  sun  at  the  same  time  is  influencing  the  earth 
more  powerfully  in  the  opposite  direction  ?  How  can  each  power  in- 
crease the  tide  on  the  further  side  from  itself,  while  the  two  powers  are 
attracting  the  earth  in  opposite  directions  ?  In  other  words,  can  the 
earth  be  influenced  in  opposite  directions  at  the  same  time  ? 

The  fact  that  there  are  tides  at  the  extremes  of  large  inland  waters, 
while  there  is  no  perceptible  rise  in  the  middle  of  those  waters,  appears 
to  conflict  with  the  idea  of  two  great  general  risings.  The  writer  in  the 
Cyclopaedia  says:  " Near  the  east  end  of  the  Mediterranean,  as  at  Mal- 
aga, a  small  tide  is  observable,  being  propagated  from  the  Atlantic  Ocean 
through  the  Straits  of  Gibraltar."  Though  I  do  not  admit  that  the  tide 
at  the  east  end  of  that  sea  is  propagated  by  the  ocean  tide,  I  quote  the 
statement  as  supporting  the  theory  of  horizontal  movement,  and  contra- 
dicting the  theory  of  perpendicular  rising.  I  ask,  if  a  horizontal  im- 
pulse or  movement,  given  at  the  Straits  of  Gibraltar,  will  produce  a  tide 
at  the  east  end  of  the  Mediterranean,  without  making  any  apparent  rise 
in  the  main  body  of  that  sea;  may  not  a  horizontal  impulse  or  move- 
ment, given  to  the  broad  oceans,  produce  tides  on  the  shores,  without 
making  any  considerable  rise  in  the  main  body  of  those  oceans  ? 

I  trust  I  have  not  misrepresented  the  old  theory.  If,  however,  I  have 
been  led  to  my  opinions  respecting  it,  by  not  understanding  the  prin- 
ciples which  determine  those  things,  then  the  opinions  can  do  no 
harm ;  for  if  the  protuberances  exist,  and  follow  the  moon  from  east  to 
west, — they  will  continue  to  exist  and  follow,  notwithstanding  my  ob- 
jections. 

In  regard  to  my  own  theory : — If  what  I  have  said  in  my  homely  way 
shall  engage  the  attention  and  consideration  of  scientific  men,  who  will 
test  the  theory  by  sound  principles,  and  by  the  facts  as  they  exist,  I  shall 
have  the  strongest  faith  that  the  day  will  come,  when  the  world  will  ac- 
cept it  as  the  true  theory. 

It  will  please  me  to  hear  from  those  who  may  be  willing  to  express 
opinions,  whether  they  approve  or  disapprove  my  views. 

DANIEL  K.  CHASE. 

CALAIS,  MAINE,  May  20,  1871. 


is  due  before  dosing  timt  M  ,he  ,os,  dot.  Itomp 

AS  STAMPED 


FORM  NO.  DD6A,  20m 


